1. Field of the Invention
The present invention is in the field of burner devices and, more particularly, an infrared radiating burner article, for generating infrared radiation.
2. Description of the Prior Art
It is presently known to provide an article, operable in the infrared radiation band of the electromagnetic spectrum, which functions as a burner to heat a product. The article utilizes the known heating properties of infrared radiation for heating the product. The article typically includes a refractory, which is a radiating body, the surface of which absorbs radiation incident thereon and emits radiation therefrom. Such refractory, when heated, transfers heat from the burner to the product being heated in a directional manner, permitting heat to be applied at predetermined locations.
The article may be utilized for various applications, and is particularly useful where substantial heat penetration is desired. Such applications may typically include the drying of material moving on a conveyor or web. Radiant gas burners require little room for installation, and may be installed where space llimitations restrict adding conventional dryers, as in ovens. Oven manufacturers use infrared gas burners as heat sources, since they provide rapid preheating of the product, and the combusted gas provides appropriate dwell-curing time temperatures. Continuous or conveyorized heat processing or drying applications are typically speeded up, and the quality improved, through the use of gas-fired infrared energy.
The article may typically comprise an atmospheric-type burner, in which air and gas are premixed to form an air/gas mixture, delivered to the burner. The air/gas mixture is ignited and directed at the top surface so as to heat the refractory. Such heating produces a flux of substantial radiance, radiating from the surface of the refractory to the product being heated.
Still further, such articles presently known are rigidly secured to a common manifold, and the entire burner and manifold assembly must be returned to the manufacturer for replacement of the burner alone. Such procedure required to replace burners is highly expensive and inefficient. When a refractory in a presently known article requires replacement, the manufacturer recommends that the entire burner should be returned to the manufacturer, as such refractory is sealed in the burner housing. Such a procedure is also very expensive and highly inefficient.
It is normally necessary, pursuant to presently known devices, to use substantial quantities of gas to attain a quantity of infrared radiation output therefrom, which is highly inefficient and costly. However, if less gas is used, less infrared radiation is generated. It is further normally necessary in such burner devices, to utilize a relatively long period of time for generating infrared radiation upon starting the system up and for dissipating infrared radiation upon shutting the system down. This approach imposes substantial expense and inefficiency upon the burner structure. The relatively long period of time required to generate infrared radiation is highly inefficient and expensive. The relatively long period of time required to dissipate infrared radiation subjects the material being heated within the range of residual infrared radiation emitted by the refractory to damage by virtue of elevation of the temperature thereof. Still further, presently known burner structures are positionable so as to radiate infrared upwardly, to prevent deterioration of the refractory surface which could occur in other positions as a consequence of the ignited air/gas mixture flowing back over the refractory surface. The intended use of the structure, however, may be such as to make orientation in a position other than such position more economical and efficient. Other orientations are not feasible with presently known devices. Still further, burners presently known may be secured to a manifold, and refractories may be secured to the burner, such as to require return of the entire assembly to the manufacturer for replacement of the burner or refractory, which are further highly inconvenient and expensive.
Thus, particular problems arise. If presently known structures are utilized, such structures utilize substantial quantities of gas in generating a quantity of infrared radiation, which is very expensive and inefficient. However, if less gas is utilized, less heat is generated, which is also highly inefficient. Further, such structures require a relatively substantial period of time to generate and dissipate infrared radiation when starting up and shutting down, resulting in inefficiencies in the operation thereof and increased expense therein, and subjecting the material being heated to possible damage thereto as a consequence of residual infrared radiation elevating the temperature thereof. Further, presently known structures may typically be oriented in one position only, such that infrared is radiated upwardly, thereby preventing use in more efficient orientations. Such burner articles may be secured to assemblies, and refractories secured to the burner, so as to require return of the entire assembly for repair or replacement of parts, which is also highly inefficient and expensive.